An air filter medium includes a first porous PTFE membrane and a second porous PTFE membrane. The air filter medium has a first main surface and a second main surface, and the first porous PTFE membrane and the second porous PTFE membrane are arranged so that an air flow moving from the first main surface to the second main surface passes through the first porous PTFE membrane and subsequently through the second porous PTFE membrane. A contact angle of the first porous PTFE membrane with water is in the range of 154° to 165°.

The present invention relates to a multilayer film for air purification and a method for manufacturing the same and, more particularly, to a multilayer film for air purification having a thin and uniform shape, thereby exhibiting a high degree of utility as a mask and an air purification filter, as well as having an excellent air purification function, and a method for manufacturing the same. The objective of the present invention is to provide a multilayer film for air purification and a method for manufacturing the multilayer film for air purification, which comprises yellow ocher-activated carbon composite particles capable of removing fine dust, bacteria, odor, VOC, etc. present in the air.

Described herein is a filter screen used to extend the life of OEM or other equipment filters by serving as a replaceable pre-filter that reduces wear and particulate build up in the OEM or other filter, as well as methods of using a filter screen to preserve filter integrity and extend filter life.

A replaceable air filter element is provided with fixation pockets configured to record corers or edges of reusable exoskeleton support frame. The exoskeleton support frame, The reusable exoskeleton support frame is adapted to detachably engage the fixation pockets to support the filter medium. The exoskeleton support frame of the filter element is configured to be reused such that only the filter medium is replaced, thereby reducing the environmental waste and making for a “green” eco-friendly air filter element.

A filter pleat pack of the present disclosure includes an air filter medium folded into pleats, wherein the air filter medium includes a laminate of a polytetrafluoroethylene (PTFE) porous membrane and an air-permeable supporting member, and the air filter medium has a shrinkage rate of 50% or more, the shrinkage rate being determined by a formula (d2−d1)/d2, where d1 is a smallest thickness of the PTFE porous membrane in a folding area of the air filter medium folded into pleats and d2 is a thickness of the PTFE porous membrane in a flat area of the air filter medium. The filter pleat pack of the present disclosure is a filter pleat pack for which a collection efficiency decrease resulting from pleating is reduced.

A vacuum cleaner has a vacuum cleaner bag having two layers made of filter material, which are joined together on at least three sides to form an inner chamber. An inflow opening is formed on a fourth side between the two layers, at least in regions, into which a connector for connecting to a vacuum cleaner can be inserted.

A filter element for an air filter assembly of an engine includes a primary filter media and a secondary filter media. The primary filter media has a plurality of pleats having first fold edges on an inlet face of the primary filter media and second fold edges on an outlet face of the primary filter media. The first and second fold edges extend from a first lateral side to a second lateral side of the primary filter media. The secondary filter media is constructed of a non-woven material and includes a first portion arranged on the inlet face of the primary filter media, a second portion secured to the first lateral side of the primary filter media, and a third portion secured to the second lateral side of the primary filter media.

A filter holding device includes an opening portion and a filter. The opening portion communicates an inside of the filter holding device with an outside of the filter holding device. The filter includes a first side and a second side. The first side faces the inside of the filter holding device. The second side faces the outside of the filter holding device. The filter has a lower weight density per unit volume at the first side than at the second side. At least a side face of the first side of the filter is covered with an air-impermeable member. The side face is a lateral face of the filter at the first side.

The invention comprises a vacuum cleaner filter bag with a bag wall, comprising: a support layer comprising recycled polyethylene terephthalate, rPET; a fine filter layer of a meltblown non-woven fabric comprising polypropylene, PP, PET and/or recycled polypropylene, rPP; and a capacity layer of a non-woven fabric comprising rPET, recycled textile material, TLO, and/or rPP; wherein the bag wall moreover comprises at least one intermediate layer formed of a non-woven fabric or a fibrous web and comprising rPP as a main component; and wherein the at least one intermediate layer is arranged between the support layer and the fine filter layer and/or between the fine filter layer and the capacity layer.

Filter media comprising a pre-filter layer and related components, systems, and methods associated therewith are provided. In some embodiments, the pre-filter layer may be designed to impart desirable properties to the filter media, such as a high gamma and/or long service life, while having relatively minimal or no adverse effects on another property of the filter media that is important for a given application. For instance, a pre-filter layer may be used to improve the upstream removal of fine particulate matter, which may clog a downstream efficiency layer comprising submicron fibers and reduce filtration performance. The pre-filter layer may be configured to increase service life and/or increase the gamma of the filter media. Filter media, as described herein, may be particularly well-suited for applications that involve filtering air, though the media may also be used in other applications.